Overview ……..……………3 Oklahoma has a very rich geologic history that spans about 1.

4 billion years,
which is a very long time. The development of our state has benefited greatly from
Mapping …………………...4-6 our rich oil and gas resources as well as our coal, minerals and rocks that are
important for constructing things such as our homes and buildings. Today, the taxes
Oil & Natural Gas ……………7-9 paid, especially by producers of oil and gas, provide much of the money needed to
run our state government, schools and universities.
Earthquakes ………………..10-11 The complex geology of Oklahoma is responsible for the Ouachita, Arbuckle and
Rocks & Minerals ……………12 Wichita Mountains, and for the ancient rivers that carved out the landscape we see
today. This landscape is favorable for the building of dams that create our many
Fossils & Dinosaurs …………..13 lakes, providing recreation, electric power, and most importantly water to sustain
us. Favorable geological conditions also have resulted in valuable ground water
Water & Aquifers ……………14-15 resources.
Our future prosperity depends on maintaining a balance between wise usage
and protection of the natural resources with which we have been provided, and
understanding geology will play a key role in this effort.

Randy Keller
Director, Oklahoma Geological Survey

Credits:
The content for Oklahoma Rocks! was developed by the Oklahoma Geological Survey with contributions by The
Oklahoma City Geological Foundation and the Oklahoma Society of Land Surveyors.
The Oklahoma Geological Survey (OGS) provides research and public services related to the state’s land, water,
mineral and energy resources and to the wise, environmentally sound use of them. The OGS is a state agency
affiliated with the University of Oklahoma College of Earth and Energy. The OGS provides resources for teachers
and students including publications such as “The Gee(WHIZ)ology of Oklahoma” and other materials for
classroom use, plus programs and activities for teachers, available at www.ogs.ou.edu.
2
 A road cut along I-35 through the
Arbuckle Mountains allows travelers
to see how rock layers are folded and
faulted by geologic processes.

Oklahoma is a state with varied, fascinating, to the left shows what we do know about stages in
and at times very complex land attributes. To a the formation of Oklahoma’s geologic resources.
degree, the state owes much of its past and current These bedrock formations of Oklahoma are
IN OKLAHOMA prosperity to the economic benefits of its natural located, recorded and studied according to their
Red rocks of western Okla- resources. Oil, natural gas, water resources, places not only on geologic maps but also on
homa formed; salt-water seas building materials, and even soils that are farmed surveying maps. The geology and human activities
deposited gypsum in what is are here because of Oklahoma’s rich geology. associated with these elements – the mapping,
now the Blaine Escarpment; Historically, Oklahoma has been a leader in oil and natural gas, local earthquakes, rocks and
uplift occurred in the Rocky petroleum exploration and production, and many of minerals, fossils and dinosaur activity, and water
Mountains from which the the scientific and engineering techniques used today and aquifers – impact each other and the state’s
debris that collected in the were developed here. The state also has important economy. The knowledge we have about it all
Panhandle formed the state’s research programs in seismology (earthquakes), continues to develop as new technologies become
largest aquifer; evidence of soil science, hydrology and water use, which available to improve the way Oklahoma’s land and
dinosaurs living in river areas are all dependent on the rocks underfoot. Even resources are mapped, studied and analyzed.
from about 205 million to 65 Oklahoma’s diverse ecosystems are here at least in As we gather each new piece of the jigsaw
million years ago. part because of geologic processes that have given puzzle that is Oklahoma’s claim to scientific history,
us mountains, plains and river bottoms. the final picture comes into focus. Will the puzzle
The oldest rocks in Oklahoma (about 1.4 billion ever be finished? No, because we’ll always have
years old!) are exposed in the eastern Arbuckle new areas to survey, new wells to drill and new
Ouachita, Arbuckle and
Wichita Mountains rose
Mountains. Geologists don’t know much about this technologies to help answer age-old questions.
above sea level; Arkoma, period, however, because most of these rocks are Prepare to learn more about (why)
Anadarko and Ardmore buried by younger rocks, and they are reached only Oklahoma rocks!
Basins formed; material that and rarely by oil and gas well drilling. The timeline
eroded off the mountains
and into the basins became
the petroleum reservoirs of
Major Geologic Provinces of Oklahoma
the state.

Covered by shallow sea. Visit nie.newsok.com for

an expanded map with
cross-section views of the
major geologic provinces.

Oldest rocks in Oklahoma formed.

3
 Map showing the base lines and principal
meridians of the Public Land Survey System.
Visit nie.newsok.com to view this
map of the entire U.S.

Mapping Overview larger area on the ground. The larger the map scale, the smaller the
second number in the ratio or fraction will be.
Maps show the distribution of features on or beneath the Earth’s
surface. Maps have been around for millennia, which attests to their
importance and the value of understanding them. While most people
Coordinate Systems
Coordinate systems are grid-based systems used to define locations
are familiar with road maps, which show the distribution of roads in
on the Earth’s surface. Traditionally, the most frequently used coordinate
an area, maps may show any variety of features, including vegetation,
system worldwide was latitude and longitude. Today, because of the
precipitation, political boundaries, topography and geology.
increasing popularity of Global Positioning Systems (GPS), the use of
Maps have many different components, including a scale and a
Universal Transverse Mercator (UTM) coordinates is becoming more
coordinate system. If the map is topographic, it also will have contours
widespread. In many states, including Oklahoma, a local system called
that show differences in elevation.
the Public Land Survey System is used.
Map Scale
Map scale is the ratio of the distance between two points on a map The Public Land Survey System in Oklahoma
and the same two points on the ground. It usually is expressed as a In the late 1800s, government surveyors were commissioned to lay
ratio, such as 1:24,000, or a fraction, 1/24,000. The first number out the public lands, then known as Oklahoma Territory, into a grid
or numerator (usually 1) represents a map distance, and the second in preparation to be sold or granted to the public. These grids were
number or denominator represents the ground distance. A scale of to be 6 miles square and were known as townships. They would be
1:24,000 means that one unit on the map represents 24,000 units on later divided into 36 smaller units, which are our modern day sections
the ground. Thus, a scale of 1:24,000 typically means that one inch on of 640 acres each. In most areas, they were then divided into even
a map is equivalent to 24,000 inches on the ground. smaller squares, or quarter sections, of 160 acres. Iron posts were set
Maps vary according to the scale of publication – large, medium at the corners of the townships and stones were placed at all of the
and small. Large-scale maps such as 1:24,000 show more detail than section and quarter corners. Some of these stones can still be found
small-scale maps such as 1:100,000, but small-scale maps depict a today if the area is wooded or has not been disturbed.

4
These diagrams show the divisions of township, range and section in the Public Land Survey System.

The point from which all these sections are set is they needed to correct for the curvature of the Earth,
known as the Initial Point. It is located on the current or eventually all of the lines would converge at the
county line between Murray and Garvin Counties North Pole. It was established that these corrections
about a mile west of Davis. The line running east-west would take place every four townships, or 24 miles
from this point is known as the Base Line and the line (4 townships x 6 miles each). These correction lines
running north-south from this point is known as the are known as Standard Parallels. The county roads as
Indian Meridian. All Oklahoma lands were laid out on we know them today were built primarily along these
this grid except for the Panhandle, which was done at section lines. If you drive north or south along one of
a later date and has its own Base Line and follows the these county roads, every 24 miles you might come
Cimarron Meridian. across a small jog in the road. This is where the original
If you look at the legal description of any property surveyors corrected their surveys.
and it reads something like Sec. 10 T2N R20W of the Land surveys are required today for receiving
Indian Meridian (or I.M. for short), this means that the building permits, for making permanent home
land is in section number 10 of the township located improvements such as adding a fence or addition to
2 north of the Base Line and 20 west of the Indian the land, and for settling disputes with neighbors over
Meridian – in other words, 12 miles (2 townships x where one property starts and the next begins. Land
6 miles each) north and 120 miles (20 townships x 6 surveys also are imperative for understanding geology.
miles each) west from the Initial Point. That places the For example, before oil and gas wells can be drilled,
land in this example in Jackson County near Altus. oil and gas companies need land surveys to know who
While surveying these townships, early surveyors owns the surface property in order to pay them for the A large stone monument marked “IP” still stands
were instructed to go due north. As they went north resources underneath it. today in a farmer’s field at the Initial Point.

5
 CROSS-SECTION THROUGH THE BIXBY 7.5’ QUADRANGLE,
Background: Portion of geologic map of
TULSA COUNTY, OKLAHOMA the Bixby Quadrangle in Tulsa County.
Thomas M. Stanley and Julie M. Chang Foreground: Cross-section through the
2009 Bixby Quadrangle.

Geologic Mapping Activities

In addition to surveying maps, another type of map is the geologic map.
Geologic maps show the rock type, age and structure of a given area. Currently,
geologic mapping in Oklahoma is done through the STATEMAP program, a joint
project between the U.S. Geological Survey and the Oklahoma Geological Survey. 1. Create a map of your neighborhood using a scale system. Be
Geologic maps have many uses. In Oklahoma, energy exploration is an sure to first decide what ratio you will use, and create a key so
important industry, and geologic maps are needed to help locate oil and gas others will be able to read your map accurately.
resources as well as industrial minerals and building materials that are important 2. Using maps linked from nie.newsok.com, answer the following
to the economy. Commercial and residential planners and engineers use geologic questions:
maps when constructing new roads, dams, pipelines, power lines, updating zoning a. In what township and range is your school located?
laws, and locating housing developments and buildings. For recreational purposes, b. In miles, how far is your town, both north or south and
geologic maps also are helpful for outdoor activities and sports such as camping, east or west, from the Initial Point?
hiking and fishing.
3. Using information on websites linked from nie.newsok.com,
The Work of a Field Geologist answer the following questions:
Geologists read studies and examine existing maps to become familiar with a. On what geologic formation is your town built?
the geology and stratigraphy of the area they will map. In the field, geologists b. What type of rock composes this formation?
look at exposed outcrops (the parts of rock formations that appear above the c. Are these rocks igneous, metamorphic or sedimentary?
Earth’s surface) to describe them in detail and map structures like folds and d. During what geologic period did these rocks form?
faults. Descriptions include information such as rock type, bedding thickness and e. Based on radiometric dating, what is the absolute age
character, grain size and shape, mineralogy, and fossil presence and colors. of these rocks?
Geologists also record information about the rocks because it helps them
understand the environment in which the rocks formed. For example, oolitic Look for more Mapping activities in Lesson 1 in the April 14 edition
limestone – rocks composed of small, spherical calcium carbonate grains – form in of The Oklahoman!
shallow marine environments.

6
 Petroleum System Processes

This graphic shows the processes involved in petroleum harvesting systems. Source rocks The blue areas in this photomicrograph of a potential reservoir made of
generate and expel hydrocarbons with increasing temperature. These hydrocarbons sandstone are pores between individual sand grains. Fluids – water, oil or
can then migrate through rocks into the reservoir, from which they displace water and natural gas – can flow through these pores. The larger the pores, the more
separate into a gas cap overlying an oil rim. oil and gas that can be stored and the better they will flow.

Putting Oklahoma on the Map Formation of Oil and Natural Gas

Oil put Oklahoma on the map, both figuratively and literally, because oil Oil and natural gas are formed by microscopic organisms that are
was the driving force behind turning Indian Territory and Oklahoma Territory deposited with sediment that eventually turns into sedimentary rock. These
into the State of Oklahoma in 1907. Oil seeps – the natural appearance of sediments, and the organic remains buried with them, are thickest where
liquid petroleum at the Earth’s surface – were recognized here long before the they accumulate in geologic basins. Within these basins the right mix of
arrival of white settlers. Native Americans knew them as “medicine springs.” temperature and pressure combine to convert these remains over millions of
The first intentional Oklahoma oil find came from a well drilled in 1889 near years into oil and natural gas. These compounds consist mostly of hydrogen
Chelsea, in Rogers County. This well produced a half barrel of oil per day and carbon, and are therefore called hydrocarbons.
and was used as “dip oil” to treat cattle for ticks. The first commercial well These hydrocarbons flow through pores between the grains that make up
in Oklahoma was the Nellie Johnstone #1 in Bartlesville, which struck oil in the rock beds, and become trapped in underground reservoirs or “pools.”
1897. In Oklahoma, most oil and gas deposits are produced from sedimentary
In the 10 years leading up to statehood, Oklahoma became the world’s rocks that were deposited during the Pennsylvanian geologic period, about
largest oil-producer, and Tulsa became known as the oil capital of the world. 318 million to 299 million years ago, but reservoirs range in age from the
Crude oil production reached about 120,000 barrels per day in 1907, the Cambrian to Permian, roughly 520 million to 250 million years ago.
year of Statehood. The oil rush continued with a steady stream of enormous Oil and gas reservoirs are found and studied by sending seismic shock
discoveries throughout the 1920s, with peak oil production occurring in waves into the ground and measuring the time it takes for the vibrations to
1927. bounce back from subsurface rocks. This data provides clues as to where oil
The average oil well now produces about two barrels a day. Each barrel and gas most likely exist, but drilling remains the only way to be certain.
holds 42 gallons of crude oil. The oil then has to be refined to be used as
gasoline, as heating oil and for other purposes. One barrel yields about 19
gallons of motor gasoline (or 10 gallons of diesel).

7
 On the Map:
Remember that land surveying This Cushing oil field, the fourth largest field
coordinates are essential to understanding in the state, was discovered in 1912 and
and locating all geologic features. The has produced about 520 million barrels of
Nellie Johnstone #1 well is listed on the oil. The photo was taken about 1918.
National Register of Historic Places at Sec.
1 T26N R12E – section 1 of the township
located 26 north of the Base Line and 12
east of the Indian Meridian, or 156 miles
Activities
north (26 townships x 6 miles each) and Energy’s Role in the Oklahoma Economy oil and gas tax revenue added about $1.35
billion to the state’s economy; in 2009 it fell to
have been drilled in Oklahoma, about
120,000 still produce. However, after a
72 miles east (12 townships x 6 miles The state’s prominent place in the oil and 1. Vehicles average roughly 18 miles per gallon in the U.S. Knowing how
each) from the Initial Point. roughly $600 million. century of exploration, future large oil and gas
gas industry is the fortunate result of being much motor gasoline can be refined from a barrel, how many miles can a
The industry’s success in finding abundant discoveries are unlikely. Still, new technology is
home to the resource-rich Anadarko, Arkoma car go on one barrel of crude oil? If every barrel produced in Oklahoma
oil and natural gas, much of it from Oklahoma, extending the life of existing fields.
and Ardmore Basins. Natural gas production were refined into gasoline, how many miles could be driven from one year
has helped make these the world’s primary Much of the oil and gas industry now
tends to be especially concentrated in and of Oklahoma’s production? The gas mileage of hybrid vehicles varies, but
energy sources. This cheap energy has been a depends on horizontal drilling technology,
near the Anadarko and Arkoma Basins, while can easily reach 50 miles per gallon. How many miles could be driven from
key factor in the prosperity and technological which has made it possible to harvest oil
most oil is located along their flanks and on the one year of Oklahoma oil production if every car were a hybrid?
advancement in the previous century; however and gas from harder-to-produce reservoirs.
Cherokee Platform.
it has also brought a dependency on fuels that Horizontal drilling is responsible for a 4 2. The U.S. now produces about 5.6 million barrels of oil a day, of which
Despite Oklahoma’s perennial image as
carries environmental liabilities. Man’s primary percent increase in U.S. oil production in Oklahoma chips in about 180,000 per day, or about 3 percent of the total. Numerous companies of all sizes were founded to help
an oil producer, natural gas has been our
primary energy resource for nearly half a
source of energy has evolved from wood to 2009, most of it from oil-shale in North Dakota. For natural gas, U.S. production totals about 71 billion cubic feet, of which produce Oklahoma’s oil bounty. Some of the larger
coal to oil and now progressively to more Another new method of retrieving oil and Oklahoma’s contribution is a little less than 7 percent of the total. If oil is
century, and today represents about 80
environmentally friendly natural gas, which gas is called hydraulic fracturing, or “fracing.” worth $75 per barrel throughout the 2010 calendar year, and the state of companies that were born in our state include:
percent of hydrocarbon production. Natural
Oklahoma has in abundance. This ensures that In fracing, millions of gallons of water or other Oklahoma receives 7 percent of this in the form of a gross production tax, • Devon Energy Corporation (Oklahoma City)
gas is the major factor determining industry
energy will be a key component of the state’s fluids mixed with chemicals are injected into how much money will oil production contribute to the state budget during • Chesapeake Energy Corporation (Oklahoma City)
activity, employment and hence income tax,
economy well into the 21st century. the ground under great pressure to create the year? What about natural gas, assuming it is worth $5 per 1,000 cubic • Phillips Petroleum Company (Bartlesville)
and represents the bulk of the state’s gross
fractures. Sand is pushed in with the water feet? • Marland Oil Company, which became Conoco (Ponca City)
production tax revenues. However, like oil,
the price of natural gas is volatile and driven
The Future to hold open the fractures, and these create
3. Research the economic impact of the oil and gas industry on a particular • Halliburton Oil Well Cementing Company (Duncan)
Nationally, the state ranks sixth in oil pathways through which the oil and gas that • Noble Drilling Corporation (Ardmore)
by factors that are unpredictable, such as the Oklahoma town. How did oil and gas production contribute to the city’s
production (behind Texas, Alaska, California, are held in otherwise impermeable rocks can • Kerr McGee Oil Corporation (Ada)
state of the economy and the severity of winter success? If production declined, how did this affect the town?
Louisiana and North Dakota), and third in flow into the wellbore. • Cities Service Oil Company (Bartlesville)
weather. The current budget shortfall is largely
gas production (behind Texas and Wyoming). Look for more Oil & Natural Gas activities in Lesson 2 in the April 21 edition • Champlin Petroleum Company (Enid)
the result of a one-year fall in the price of
Of the approximately 600,000 wells that of The Oklahoman!
natural gas by more than 50 percent. In 2008,

8 9
 Overview more common. Approximately 30 times more energy is released for
each increase of one magnitude unit. This means that the January 14,
Oklahoma Rocks!, shakes, rattles and rolls! In Oklahoma, ground
2010, magnitude 7.0 earthquake in Haiti released nearly 200 times
motion caused by earthquakes is recorded by the Oklahoma Geological
more energy than the largest Oklahoma earthquake ever recorded by
Survey through a statewide network of seismograph stations. The Survey’s
instruments, which was a 5.5.
main recording and research facility is located near Leonard, in Tulsa
Intensity is reported on the Modified Mercalli scale, a subjective
County. The first seismographs were installed in Oklahoma in 1961.
measure based on eyewitness accounts. Intensities are rated on a 12-level
Earthquakes before then were recorded in other states or by witnesses’
scale ranging from barely perceptible to total destruction.
accounts. Earthquakes have occurred in 72 Oklahoma counties;
Washington, Nowata, Craig, Adair and Jackson Counties have no
known earthquakes.
Cause of Earthquakes
On average about 50 measurable earthquakes occur each year in
Measuring Earthquakes Oklahoma; only a few are actually felt. Since 1977, more than 1,800
earthquakes have been located in Oklahoma. Typical Oklahoma
The most common ways to express the size of earthquakes are by their
earthquake magnitudes range from 1.8 to 2.5, with shallow focal depths
magnitude and intensity. Earthquake magnitude is related to the seismic
of less than three miles. Focal depths are the place under the Earth where
energy released at its center. The most famous is the Richter scale, though
the ground begins to rupture.
there are many other ways of determining magnitude that are becoming

Oklahoma earthquakes from 1897 to 2002 and the

locations of major recording sites in the state.

10
 The earliest documented earthquake in Oklahoma
occurred on October 22, 1882, and while it cannot be
precisely located, it produced the strongest shaking, with
an intensity of VIII on the Modified Mercalli scale reported
at Fort Gibson in Indian Territory. On April 9, 1952, the
largest instrumentally recorded earthquake in Oklahoma
occurred near El Reno. This earthquake had a magnitude
of 5.5 and caused a crack in the state Capitol building in
Oklahoma City. Its effects were felt as far away as Austin,
Texas, and Des Moines, Iowa.
Small earthquakes, such as those that have been
occurring over the last two years in eastern Oklahoma
County, can and do occur nearly everywhere on the
planet. The U.S. Geological Survey estimates that more
than 3,000 of these earthquakes occur around the world
every day; most go unnoticed. Almost all earthquakes
occur on pre-existing faults, which range dramatically in
size. One of the largest faults in Oklahoma is the Meers
Fault in southwestern Oklahoma.
Oklahoma’s faults are small compared to faults
associated with plate tectonic boundaries, along which
very large earthquakes occur. Plate tectonic boundaries
are where one plate of the Earth’s lithosphere, the outer
solid part of the Earth, moves past another at a rate
similar to the speed at which your fingernails grow.
Earthquakes occur at plate boundaries because the
rocks at these plate boundaries do not slide smoothly
past each other, but instead move abruptly past each
other. Friction causes the passing tectonic plates to remain
“locked” for some amount of time while stress builds on
The thin, green diagonal line in the photo is the
the fault. An earthquake occurs when the stress within the surface expression of the Meers Fault in southwestern
Earth exceeds the strength of a fault. Stresses build up on Oklahoma. Some of the fault is visible from the air in
plate tectonic boundary faults much more rapidly than parts of Comanche County.
on the smaller faults in Oklahoma and across the mid-
continent, which is why the great majority of earthquakes Activities
occur along plate boundaries.

1. Earthquakes are most likely to occur in locations where they have occurred before.
What areas in Oklahoma are most likely to have an earthquake in the future?
2. Now that scientists can measure the magnitude of an earthquake, why do you think they
still use the Modified Mercalli scale to describe earthquakes?
On the Map:
3. The Oklahoma Geological Survey posts information about recent Oklahoma
The 1952 earthquake that rattled El Reno earthquakes on its website at ogs.ou.edu. Visit the site and answer these questions:
and surrounding states originated in a. When did the most recent Oklahoma earthquake happen?
Sec. 26 T11N R6W. This corresponds b. What was its magnitude?
to a latitude of 35.4°N and longitude of c. Were there reports that the earthquake was felt?
97.8°W. d. Where did it take place according to land survey coordinates?

Look for more Earthquakes activities in Lesson 3 in the April 28 edition of The Oklahoman!

11
 Oklahoma’s Rocks and Minerals
Oklahoma’s diverse geology has resulted in a state rich in rock and
mineral resources. A mineral is made of just one substance that has a
crystalline structure, even if it doesn’t look like a crystal to the plain eye. A
rock is made up of more than one type of mineral.
Many Oklahomans benefit directly and indirectly from Oklahoma’s
mineral wealth. Oklahoma’s rock and mineral industry is a $600 million
per year business that provides jobs for about 30,000 people. These
industrial minerals may seem commonplace but are critical for maintaining
and building the state’s and country’s infrastructure. By far the most
valuable commodity is crushed stone – mostly limestone – a key ingredient
of concrete and asphalt. Second are sand and gravel, which also are used
in aggregate materials.
Oklahoma is the leading producer in the U.S. of the mineral gypsum
in the U.S., the primary material in wallboard. Some of the gypsum is so
pure that it is of pharmaceutical grade and is used in some foods and
pills. Gypsum also forms caverns throughout western Oklahoma. In fact,
the longest gypsum cave in the world outside of Russia is Jester Cave in
Greer County, with more than 33,000 feet of passageways. The largest
gypsum cave in the world that is open to the public is Alabaster Cavern in
northwestern Oklahoma.
In the far northeastern part of the state, lead and zinc mines supported Building materials produced
On the Map:
an industry that made Miami, Oklahoma, the leading zinc producer in the from the state’s rock and min-
U.S. from 1918 to 1945, when 1.3 million tons of lead and 5.2 million eral resources await shipment Jester Cave is located in Sec. 26 T7N
tons of zinc were produced. That is enough zinc to supply parts for half a from an Oklahoma quarry. R24W – 42 miles north and 144 miles
billion cars. west from the Initial Point.
Coal, which is still burned to provide about 60 percent of Oklahoma’s
electricity needs, could be considered an “energy mineral,” but it is not a
mineral at all. It is a hydrocarbon, similar in many respects to oil.
Activities

1. Look around your classroom and identify items made from

minerals, such as bricks and light bulbs. Remember, plastics are
made from petroleum and should be considered a mineral product.
Which were produced from rocks or minerals that can be found in
Oklahoma?

2. Coal was heavily mined throughout much of eastern Oklahoma

in its early history. Old and abandoned surface and underground
mines, some of which now present geologic hazards, extend
from Craig County in the north to Atoka County in the south. The
Oklahoma Conservation Commission is actively reclaiming these old
mines and making the land safe. What are some of the hazards that
might be associated with Oklahoma’s old coal mines?

Look for more Rocks and Minerals activities in Lesson 4 in the May 5
edition of The Oklahoman!

12
Oklahoma Fossils
A fossil is any evidence of ancient life that has been preserved in the
Earth’s crust. This includes animals, plants and even traces of animal
movement or behavior such as trails and dinosaur footprints preserved
in rock. A fossil can be preserved as whole skeletal material, such as a
fossilized clam or dinosaur bone, or as an imprint, cast or mold within a
rock.

Dinosaurs in Oklahoma
Dinosaurs probably once roamed throughout the area we now call
Oklahoma, but most of the evidence for this has been removed through
erosion. Rocks deposited during Mesozoic times (the “Age of the
Dinosaurs”) are exposed in southeastern Oklahoma and in northwestern
Cimarron County, and dinosaur bones have been found in both areas.
Outcrop areas of the Antlers Formation (Cretaceous period) of Atoka
County and Morrison Formation (Jurassic period) have proven productive
in the past and can be located using geologic maps.
During the Early Cretaceous period, between 146 million and
100 million years ago, an enormous meat-eating dinosaur called
Acrocanthosaurus atokensis roamed coastal areas in what is now Atoka
County. Fossil remains show the animal could have been 18 feet tall and
43 feet from head to tail, about the size of a trailer on a tractor-trailer rig,
and nearly the size of Tyrannosaurus rex, the world’s largest meat eater.
The state fossil of Oklahoma is Saurophaganax maximus. The only
known skeletal remains of this carnivorous dinosaur were found about 80
years ago in the Morrison Formation in Cimarron County. The dinosaur
was about 40 feet long, weighed approximately 2 tons, and is believed to
have been as ferocious as Tyrannosaurus rex.

On the Map:
Acrocanthosaurus skeletons were found in
Atoka County farmlands, more specifi-
cally in Sec. 26 T4S R14E.

Activities 2. Dinosaur footprints can be observed

in a stream bed near Kenton in the
northwestern corner of the Panhandle.
Search The Oklahoman archives to learn
1. Using the map above, estimate how
more about what’s there. How have area
far your town is from the site where
residents reacted to the discovery of
Acrocanthosaurus fossils have been found
evidence that dinosaurs once lived there?
in Oklahoma. Estimate how far your town
was from the coastline during the Early
Look for more Fossils and Dinosaurs activi-
Cretaceous period.
ties in Lesson 5 in the May 12 edition of
The Oklahoman!

13
 Water in Oklahoma
Oklahoma has an abundance of clean, fresh water, but that water is
not distributed evenly throughout the state. The Panhandle receives less
than 24 inches of rain each year, and the rainfall is not enough to meet
agricultural needs. Therefore, water must be drawn from lakes, streams
and subsurface aquifers. The southeastern part of the state, on the other
hand, receives plenty of rainfall – more than 52 inches a year in some
places. Streams and lakes there generally are full. However, water
quality can be an issue. This dichotomy highlights the two primary issues
concerning Oklahoma’s water – quantity and quality.

Water Uses
The top use (41 percent) of water in Oklahoma is public water supply,
which includes domestic, commercial and industrial uses. Irrigation is
second (32 percent), and livestock and aquaculture is third (12 percent).
In all, about 1.75 million acre-feet of water was used in Oklahoma in
2005. An acre-foot is the volume of water it takes to cover one acre to a
depth of one foot. One acre-foot equals 325,851 gallons.
In addition to water supply, we use water for a variety of recreational
activities such as fishing and boating, and wildlife make use of the water
as well. By building dams, we can control the flow of water to prevent
floods and to generate hydroelectric power.

Water Sources
Oklahoma depends on two major sources of water besides rain
to supply its citizens, businesses and agriculture – surface water and
groundwater. Surface water occurs in the state’s streams, rivers, lakes and
reservoirs. About 167,000 miles of rivers and streams exist in Oklahoma.
Oklahoma’s rivers were largely established during the most recent Ice
Age, which lasted from 1.8 million years ago until 10,000 years ago.
In addition, about 1,400 square miles of water area are present in its
ponds, lakes, and reservoirs – larger than the state of Rhode Island! Very
few of Oklahoma’s lakes are natural; only the oxbow lakes along the Red
River and the seasonal playa lakes of the Panhandle are not formed by
dammed streams or rivers. About 63 percent of Oklahoma’s water use
comes from surface water sources.
Groundwater comes in two types: alluvial aquifers and bedrock
aquifers. Alluvial aquifers consist of gravel, sand and clay and are
a result of water filling muddy channels in flood plains. The water in Turner Falls. Used
bedrock aquifers comes from small pore spaces between the individual with permission,
sand grains that make up the rock or from fractures that break up the courtesy of the
Oklahoma Water
On the Map:
rock. Oklahoma has 16 bedrock aquifers formed between 515 million Resources Board.
and 10 million years ago. Water from the Ogallala Aquifer is an important
A growing demand for clean water, combined with the uneven part of life in northwest Oklahoma. Guymon, the
distribution of rainfall and the potential effects of a changing climate, largest town in the Panhandle, depends on the
require that Oklahomans manage these water resources with a great aquifer for much of the area’s agricultural and
deal of care, including being conscious of uses that waste or contaminate economic growth. Guymon is located in Sec. 3 T3N
water. R15E, based on the Panhandle’s Base Line and the
Cimarron Meridian.

14
 Activities

1. Find out where the water you use in your house comes from. If you live in a rural area and
have your own well, find out how deep the well is. If you live in a town or city with its own public
water supply, call the local utilities department and find out how much of your water comes from
surface sources (such as a reservoir) or from water wells (such as an aquifer).
2. You use water for many activities around your home. Listed below are some uses for water.
Rank them in order of importance with 1 being the most important and 10 being the least,
meaning the easiest to give up in a severe drought. Compare how you ranked these activities with
your classmates.
_____Washing the dishes
_____Drinking water
_____Water used for cooking
_____Washing the dog
_____Watering the lawn and garden
_____Washing the car
_____Taking a shower or bath
_____Washing clothes
_____Mopping the floors
_____Flushing the toilet

Take the questionnaire at http://ga.water.usgs.gov/edu/sq3.html to determine how much water Dam in the Wichita Mountains area. Used with
your family really uses in a day. permission, courtesy of the Oklahoma Water
Resources Board.

Look for more Water and Aquifers activities in Lesson 6 in the May 19 edition of The Oklahoman!

OKLAHOMA SOCIETY OF
LAND SURVEYORS
You may have seen one of us surveying the streets in your neighborhood. Did you
know that land surveyors also map rugged outdoor terrain and underwater surfaces,
work as mapmakers and computer programmers, assist in police investigations, and
own their own businesses?
Recognizing that the true merit of a profession is determined by the value of its
services to the society, the Oklahoma Society of Land Surveyors dedicates itself
to the promotion and protection of the profession of land surveying as a social and
economic influence vital to the welfare of its society, community and state.

Scholarships are avilable to help those furthering their

education in a survey-related field.
Learn more at www.osls.org